Scientists have developed a drug that could slow the progression of Alzheimer’s, research suggests.
A team from the pharmaceutical giant Biogen found the IV medication aducanumab may reduce “clinical decline” by up to 40% over 18 months.
Patients also demonstrated improvements to their memory and ability to carry out day-to-day tasks, such as cleaning, laundry and paying bills.
Biogen plans to seek approval from the US Food and Drug Administration (FDA) early next year. If granted, aducanumab would be the first drug that “reduces clinical decline” in Alzheimer’s.
How common is Alzheimer’s - and dementia?
Dementia is the “umbrella term” for disorders that trigger a loss of brain function.
It affects around 850,000 people in the UK, of which 62% have Alzheimer’s, Alzheimer’s Society statistics show.
In the US, 5.8 million people are living with the disease, according to the Alzheimer’s Association.
Alzheimer’s has no “current cure”, with medication only “temporarily reducing symptoms”, the NHS reports.
It has reportedly been 16 years since the FDA last reviewed an Alzheimer’s treatment application, with need for an effective drug now “dire”, Reuters reported.
Biogen terminated its aducanumab trials in March after a “futility analysis” showed it was “unlikely to met its primary endpoint”.
After looking at additional data of more than 3,200 patients, however, the company found the drug is in fact “pharmacologically and clinically active”.
Results - announced during a webcast - suggest early-stage Alzheimer’s patients taking aducanumab had a 40% improvement on “daily living” and “cognitive impairment” scores compared to those on placebo.
Brain scans also showed reduced amyloid beta (a naturally-occurring protein) plaques. In Alzheimer’s, the protein is thought to clump together, collecting between neurones and disrupting cell function.
Experts caution, however, while low doses of aducanumab cleared beta plaques, this only corresponded with symptom improvement at high doses.
“Anti-amyloid treatments could be borderline of driving efficacy for many patients,” Dr Diego Gomez-Nicola, from the University of Southampton, said.
Aducanumab was initially tested on around 1,650 people at a low dose to ensure safety. When this came back “clear”, the same number got a higher dose, which boosted the drug’s effectiveness.
“The question now is whether aducanunab should be approved, or whether a final trial of the full high dose aducanumab is needed to be sure of these benefits,” Professor Clive Ballard, from the University of Exeter, said.
Muddled methods and the reporting of “partial results” has left some questioning if the treatment is ready for patients.
Approving a drug that has dubious efficacy could be financially and medically damaging for US patients, while also giving pharma companies less incentive to develop new treatments, Associated Press reported.
An additional late-stage trial, however, would take years to complete.
If approved by the FDA based on existing data, aducanumab would be the “first therapy to demonstrate removing amyloid beta results in better clinical outcomes”.
“This large dataset represents the first time a study has demonstrated that clearance of aggregated amyloid beta can reduce the clinical decline of Alzheimer’s disease, providing new hope for the medical community, the patients, and their families,” trial leader Dr Anton Porsteinsson said.
While US approval may be imminent, Biogen will “continue dialogue with regulatory authorities in international markets including Europe and Japan”.
“These results are hugely important for the field, as for the first time demonstrate efficacy of a treatment for Alzheimer’s disease,” Dr Gomez-Nicola said.
“However, there is room for improvement, as the efficacy was mostly observed by the end of the trial, after 78 weeks of treatment, generating a challenging clinical prospect.
“Despite these caveats, today is a bright day for the fight against dementia, and finally the field is starting to approach an effective treatment for this devastating disease.”
Dr Gomez-Nicola was not the only expert to question whether aducanumab’s efficacy kicks in quickly enough.
“It’s now also the role of the drug regulators to scrutinise the data to find out if on balance, there is a benefit to people with Alzheimer’s disease,” Dr James Pickett, from the Alzheimer’s Society, said.
“With very few other treatment options for Alzheimer’s people may ask, ‘what is there to be lost in making this drug available now?’, but it’s crucial we fully understand the impact and safety of this drug.”
Biogen reported the most common side effects as “brain swelling” and headache. The swelling usually resolved within four-to-16 weeks and was not a long-term concern, it added.
Dr Ronald Petersen, from Mayo Clinic, told Reuters: “The side effects are there. They’re not zero but I think they’re manageable.”